Salam - got proposed to after a 5 minute chat, unsure what to do

Salam, I want to start by saying I’m a revert and still learning how to handle social situations, so please be gentle if some questions sound silly. A bit of background: I saw a brother praying some time ago and later approached him to start a conversation. I don’t have many Muslim brothers or sisters I can practice socializing with, and some siblings encouraged me to push past my anxiety and be more outgoing. The chat was short - I asked where he was from (I’ll keep that private for safety). He mentioned family and upbringing so I knew he was Muslim, but I still asked to be sure. Then he began asking me questions and within minutes started calling me cute and flirting. He said he was looking for someone to marry and asked for my number. I gave it to him mostly out of safety concerns because in the past when men asked for my number they immediately called or texted to make sure it showed up on my phone - which he did. Later he kept texting and calling me. When I didn’t answer because I was busy, he accused me of being a bad and fake Muslim. I spoke to a brother I do know and he said that usually proposals or serious approaches don’t happen like that, but it can happen and I should be ready for it sometimes. Is that true? I felt the compliments were quite intimate and I find it hard to believe that’s just normal. Edit to clarify a few things since there’s been some confusion: 1) I wasn’t looking for marriage at that moment, I was just trying to be social in a public place. 2) I gave him my number out of concern for my safety and because he called right away to confirm it. 3) I don’t understand why I’m being blamed for his inappropriate behavior. Any advice from brothers and sisters on how to handle situations like this or what boundaries I should keep would be really appreciated. JazakAllah khair.